[Lf] LF: RX Input filters

[Andre' Kesteloot]

Dave Sergeant wrote:

> >From Dave G3YMC
>
> I also use a sharply tuned front end to my receiver, having a fixed tuned
> circuit at the input of my receive converter and a second one at the output
> of the FET preamp.  Bandwidth is around a couple of kHz, which is adequate.
> DCF39 is already down on the filter slope and is probably why I give lower
> reports on it than some.  I suffer no signs of receiver crossmod.  The
> circuit can be found on my web site.
>
> Sound bias oscillator transformers from scrap VCRs make ideal transformers
> for this purpose - you will fiind one in the bias oscillator of virtually
> every video made, audio tape recorder ones may also be suitable.  The
> secondary high output winding of these transformers usually has an
> inductance of 1-2mH, and can be easily resonated on 136.
>
> 73s Dave G3YMC
> dsergeant at iee.org
> http://ourworld.compuserve.com/homepages/sergeantd